Separation apparatuses for separating sheets of brittle material and methods for separating sheets of brittle material

ABSTRACT

Methods and apparatuses for separating sheets of brittle material are disclosed. According to one embodiment, a separation apparatus for separating a sheet of brittle material includes a first separation cam positioned adjacent to a sheet conveyance pathway and a second separation cam positioned opposite from and downstream of the first separation cam. The first and second separation cams may be rotated such that the contact faces of the separation cams periodically extend across a centerline of the conveyance pathway. Rotation of the first and second separation cams may be synchronized such that at least the portion of the contact face of the first separation cam and at least the portion of the contact face of the second separation cam periodically extend across the centerline of the conveyance pathway at a separation time and periodically do not extend across the centerline of the conveyance pathway at a non-separation time.

BACKGROUND

1. Field

The present specification generally relates to the manufacture ofdiscrete sheets of brittle material, such as glass, ceramic or the like,and, more specifically, to apparatuses for separating sheets of brittlematerial from continuous ribbons of brittle material and methods forseparating sheets of brittle material from continuous ribbons of brittlematerial.

2. Technical Background

Sheets of brittle material, such as sheets of glass or ceramic material,may be formed as continuous ribbons. For example, continuous glassribbons are commonly formed by downdraw processes, such a fusion drawprocesses or slot draw processes. As the molten glass is drawn, theglass cools and solidifies. Ultimately, individual sheets of glass aresectioned from the continuous glass ribbon. These individual sheets ofglass sectioned from continuous glass ribbons can be used in a varietyof devices including flat panel displays, touch sensors, photovoltaicdevices and other electronic applications.

The rate of ribbon formation is often adjusted to accommodate the speedof manufacturing processes downstream of the ribbon formation as thecycle time of such processes (such as separation processes and the like)are often slower than the maximum rate of ribbon formation. For example,in continuous glass ribbon forming operations, the glass ribbon is oftensegmented in to discrete glass sheets utilizing equipment that trackswith and attaches to the continuous glass ribbon as the glass ribbon isconveyed in a draw direction. Once the separation operation iscompleted, the equipment detaches from the glass ribbon and cyclesupstream to repeat the process. The cycle time of these operations isslower than the maximum rate of ribbon formation and, as such, the rateof ribbon formation is reduced to accommodate the cycle time of theseparation process. However, reducing the cycle time of the processesalso reduces production throughput.

Accordingly, a need exists for alternative methods and apparatuses forseparating discrete sheets of brittle material from continuous ribbonsof brittle material.

SUMMARY

In one embodiment, a separation apparatus for separating a sheet ofbrittle material along a scoring line may include a first separation campositioned adjacent to a conveyance pathway. The first separation cammay be rotatably coupled to a first drive mechanism rotating the firstseparation cam about a first axis of rotation. The first drive mechanismmay rotate the first separation cam such that at least a portion of acontact face of the first separation cam periodically extends across acenterline of the conveyance pathway. The first drive mechanism may besynchronized with a draw rate of the sheet of brittle material such thatat least the portion of the contact face of the first separation camextends across the centerline of the conveyance pathway at a separationtime and periodically does not extend across the centerline of theconveyance pathway at a non-separation time.

In another embodiment, a method for separating a glass substrate mayinclude conveying a scored glass ribbon on a conveyance pathway in aconveyance direction. The scored glass ribbon may be directed between afirst separation cam and a second separation cam. The second separationcam may be positioned downstream of the first separation cam in theconveyance direction. The first separation cam and the second separationcam may be positioned on opposite sides of a centerline of theconveyance pathway. The first separation cam may be rotated such that atleast a portion of a contact face of the first separation cam isperiodically positioned across the centerline of the conveyance pathwayand the contact face of the first separation cam periodically contacts afirst surface of the scored glass ribbon and displaces at least aportion of the scored glass ribbon from the centerline of the conveyancepathway in a first displacement direction. The second separation cam maybe rotated simultaneously with the first separation cam such that atleast a portion of a contact face of the second separation cam isperiodically positioned across a centerline of the conveyance pathwayand the contact face of the second separation cam periodically contactsa second surface of the scored glass ribbon and displaces at least aportion of the scored glass ribbon from the centerline of the conveyancepathway in a second displacement direction opposite the firstdisplacement direction. The simultaneous displacement of the scoredglass ribbon in the first displacement direction and the seconddisplacement direction separates the scored glass ribbon along a vent inthe scored glass ribbon.

In yet another embodiment, a method for forming a glass substrateincludes drawing a continuous glass ribbon in a substantially verticaldirection from a forming apparatus. The continuous glass ribbon may bescored to form a vent as the continuous glass ribbon is drawn in thesubstantially vertical direction. Thereafter, a first portion of thecontinuous scored glass ribbon may be periodically displaced in a firstdirection which is non-parallel with the substantially verticaldirection as the continuous scored glass ribbon is drawn in thesubstantially vertical direction. Additionally, a second portion of thecontinuous scored glass ribbon may be periodically displaced in a seconddirection opposite the first direction as the continuous glass ribbon isdrawn in the substantially vertical direction. The second portion of thecontinuous scored glass ribbon may be downstream of the first portion ofthe continuous scored glass ribbon. The second portion of the continuousscored glass ribbon is displaced simultaneously with the first portionof the continuous scored glass ribbon such that a glass substrate isseparated from the continuous glass ribbon along the vent.

Additional features and advantages of the embodiments described hereinwill be set forth in the detailed description which follows, and in partwill be readily apparent to those skilled in the art from thatdescription or recognized by practicing the embodiments describedherein, including the detailed description which follows, the claims, aswell as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The drawings illustrate the various embodiments describedherein, and together with the description serve to explain theprinciples and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts a cross section of a separation apparatusfor separating a sheet of brittle material according to one or moreembodiments shown and described herein;

FIG. 2 schematically depicts an isometric view of the separationapparatus of FIG. 1 according to one or more embodiments shown anddescribed herein;

FIG. 3 schematically depicts an enlarged cross section of the separationapparatus of FIGS. 1 and 2 indicating the spatial orientation of theseparation cams and the conveyance pathway formed therebetween,according to one or more embodiments shown and described herein;

FIG. 4 schematically depicts the first separation cam and secondseparation cam of the separation apparatus of FIGS. 1 and 2 in aseparation orientation, according to one or more embodiments shown anddescribed herein;

FIG. 5 schematically depicts a cross section of an alternativeembodiment of a separation apparatus in which the separation cams arecircular in cross section, according to one or more embodiments shownand described herein;

FIG. 6 schematically depicts a cross section of an alternativeembodiment of a separation apparatus in which the separation cams areelliptical in cross section, according to one or more embodiments shownand described herein;

FIG. 7 schematically depicts the separation sweep areas of the first andsecond separation cams of the separation apparatuses described herein;

FIG. 8 schematically depicts a cross section of an alternativeembodiment of a separation cam comprising a roller formed from a nosingmaterial;

FIG. 9 schematically depicts an alternative embodiment of a separationapparatus which includes four separation cams;

FIGS. 10 and 11 schematically depict a separation apparatus being usedto separate a glass substrate according to one or more embodiments shownand described herein;

FIG. 12 schematically depicts a separation apparatus with a singleseparation cam being used to separate a glass substrate according to oneor more embodiments shown and described herein; and

FIG. 13 schematically depicts a glass manufacturing apparatus whichincludes a separation apparatus for separating glass substrates fromcontinuous glass ribbons, according to one or more embodiments shown anddescribe herein.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of apparatuses andmethods for separating sheets of brittle material from continuousribbons of brittle material, examples of which are illustrated in theaccompanying drawings. Whenever possible, the same reference numeralswill be used throughout the drawings to refer to the same or like parts.One embodiment of a separation apparatus for separating substrates ofbrittle material, such as glass sheets or the like, is schematicallydepicted in FIG. 2. The apparatus generally comprises a first separationcam positioned adjacent to a conveyance pathway and a second separationcam positioned opposite from and downstream of the first separation camon the conveyance pathway. The first and second separation cams arerotatably coupled to drive mechanisms which rotate the cams such that atleast the portion of the contact face of the first separation cam and atleast the portion of the contact face of the second separation camperiodically extends across the centerline of the conveyance pathway ata separation time. When the first separation cam and the secondseparation cam extend across the centerline of the conveyance pathway atthe same time, the cams displace a scored segment of the continuousribbon of brittle material in opposite directions, thereby separatingthe segment from the remainder of the continuous ribbon along the scoreline. The separation apparatus and methods for separating substrates ofbrittle material will be described in more detail herein with specificreference to the appended drawings.

Referring now to FIGS. 1-3, one embodiment of a separation apparatus 100for separating a sheet of brittle material from a continuous ribbon ofbrittle material, such as glass, ceramic or the like, is schematicallydepicted. The separation apparatus 100 generally comprises a firstseparation cam 102 and a second separation cam 104. The first separationcam 102 and the second separation cam 104 are supported in a frame 110such that the first separation cam 102 and the second separation cam 104are rotatable with respect to the frame 110. In the embodimentsdescribed herein, the first separation cam 102 and the second separationcam are positioned on opposite sides of a conveyance pathway 122 (FIG.3) with the second separation cam 104 offset from the first separationcam 102 in a downstream direction (i.e., in the −z direction of thecoordinate axes depicted in the figures). In the embodiments describedherein, the conveyance pathway 122 is vertically oriented (i.e., theconveyance pathway 122 extends in the +/−z-directions of the coordinateaxes depicted in FIGS. 1-3). However, it should be understood that, inother embodiments, the conveyance pathway may be horizontally orientedor, alternatively, oriented at an angle between horizontal and vertical.In the embodiment of the separation apparatus 100 depicted in FIG. 2 theseparation apparatus is depicted with substantial spacing between thefirst separation cam 102 and the second separation cam 104 for purposesof illustration and clarity. In practice, the spacing between the firstseparation cam 102 and the second separation cam 104 is much less tofacilitate contacting and displacing a continuous ribbon of brittlematerial drawn on the conveyance pathway 122 between the firstseparation cam 102 and the second separation cam 104, as depicted inFIG. 11. For example, the spacing between separation cams can be equalto or less than 1 mm, depending on the thickness of the continuousribbon of brittle material.

The first separation cam 102 and the second separation cam 104 may becoupled to a rotational mechanism which actively rotates the firstseparation cam 102 and the second separation cam 104 with respect to theframe 110. For example, in the embodiment of the separation apparatus100 depicted in FIG. 2, the first separation cam 102 is coupled to afirst drive mechanism 106 which, in this embodiment, is a stand-alonedrive source, such as a servo motor or the like. Similarly, the secondseparation cam 104 is coupled to a second drive mechanism 108 which, inthis embodiment, is a stand-alone drive source, such as a servo motor orthe like. The first and second drive mechanisms 106, 108 are capable ofrotating the first separation cam 102 and the second separation cam 104with respect to the frame 110. In addition, in embodiments where thefirst and second drive mechanisms 106, 108 are servo motors, asdescribed above, the first and second drive mechanisms 106, 108 may becoupled to a controller (not shown) such that the first and second drivemechanisms 106, 108 may be synchronously driven.

While the drive mechanisms 106, 108 of the embodiment of the separationapparatus 100 depicted in FIGS. 1 and 2 are described as being servomotors, it should be understood that, in alternative embodiments, thedrive mechanisms 106, 108 may be transmission systems, such as gears,belts or the like, which rotatably couple the first separation cam 102and the second separation cam 104 to a common drive source, such as aservo motor or the like thereby facilitating rotation of the firstseparation cam 102 and the second separation cam 104 with respect to theframe 110.

Still referring to FIGS. 1-3, in the embodiments described herein, theseparation cams 102, 104 are attached to the drive mechanisms 106, 108,respectively, such that the first separation cam 102 is rotated about afirst axis of rotation 118 and the second separation cam 104 is rotatedabout a second axis of rotation 120. In the embodiments describedherein, the first axis of rotation 118 and the second axis of rotation120 are generally parallel with one another. Specifically, both thefirst axis of rotation 118 and the second axis of rotation 120 aregenerally parallel to the x-axis of the coordinate axes depicted in FIG.1-3. As noted hereinabove, the second separation cam 104 may be offsetfrom the first separation cam 102 in a downstream direction.Accordingly, the second axis of rotation 120 corresponding to the secondseparation cam 104 is offset from the first axis of rotation 118corresponding to the first separation cam 102.

Referring now to FIG. 3, the separation cams 102, 104 are constructedsuch that the separation cams are not circular-symmetric about theirrespective axes of rotation which, in turn, allows the separation camsto be periodically engaged (and periodically disengaged) from a ribbonof brittle material drawn along the conveyance pathway. Specifically,the separation cams 102, 104 are each constructed with contact faces114, 116 for engaging with opposing surfaces of a ribbon of brittlematerial drawn along the conveyance pathway 122. In a cross section ofthe separation cam perpendicular to the axis of rotation, the contactfaces 114, 116 of each separation cam 102, 104 generally have aseparation radius r_(s) (measured from the center of the axis ofrotation to the contact face) which is greater than the non-separationr_(ns) (measured from the center of the axis of rotation to a point onthe surface of the cam) of the remainder of the separation cam. In theembodiments of the separation cams 102, 104 depicted in FIGS. 1-3, thisis accomplished by constructing the separation cam such that the cam hasa rectangular extension which extends from a circular main body andlocating the axis of rotation at the center of the circular main body.Accordingly, for a sheet of material positioned at or within theseparation radius r_(s) of the separation cam, rotating the separationcam about the axis of rotation of the separation cam causes the contactsurface to periodically contact the sheet of material and toperiodically not contact the sheet of material.

Referring now to FIGS. 3 and 4, in the embodiments of the separationapparatus 100 shown and described herein, the separation cams 102, 104are positioned relative to the conveyance pathway such that the contactfaces 114, 116 of the respective separation cams 102, 104 periodicallyextend across a centerline C_(L) of the conveyance pathway 122 as theseparation cams 102, 104 are rotated about their respective axes ofrotation, as depicted in FIG. 4. Specifically, the separation cams arepositioned such that the separation radius r_(s) of the separation camsis greater than or equal to the distance d_(CL) between the center ofthe axis of rotation of the separation cam and the center line C_(L) ofthe conveyance pathway 122. Moreover, to ensure that the separation cams102, 104 are periodically disengaged from ribbons of brittle materialdrawn on the conveyance pathway 122, the separation cams 102, 104 arepositioned such that the distance d_(CL) between the center of the axisof rotation of the separation cam and the center line C_(L) of theconveyance pathway 122 is greater than the non-separation radius r_(ns)of the separation cam.

While FIGS. 3-4 schematically depict separation cams with a specificcross sectional shape which may be utilized to achieve theaforementioned orientations relative to the centerline of the conveyancepathway, it should be understood that separation cams with other crosssectional configurations may be utilized to achieve the sameorientations with respect to the centerline of the conveyance pathway.

Referring to FIG. 5 by way of example, FIG. 5 schematically depicts anembodiment of a separation apparatus in which the first separation cam302 and the second separation cam 304 are circular in cross section. Inthis embodiment, the first axis of rotation 318 of the first separationcam 302 is non-concentric with the center of the first separation cam302. Similarly, the second axis of rotation 320 of the second separationcam 304 is non-concentric with the center of the second separation cam304. The configuration of these separation cams enables the separationcams to be positioned such that the separation radius r_(s) of theseparation cams is greater than or equal to the distance d_(CL) betweenthe center of the axis of rotation of the separation cam and the centerline C_(L) of the conveyance pathway 122, as described above, and thatthe distance d_(CL) between the center of the axis of rotation of theseparation cam and the center line C_(L) of the conveyance pathway 122is greater than the non-separation radius r_(ns) of the separation cam,also as described above.

Alternatively, the first and second separation cams may be elliptical incross section as shown in FIG. 6. Specifically, the first separation cam402 may be elliptical in cross section with a major axis and a minoraxis. The separation radius r_(s) of the first separation cam 402generally corresponds to the major axis of the ellipse while thenon-separation radius r_(ns) of the first separation cam generallycorresponds to the minor axis of the ellipse. While the first axis ofrotation 418 of the first separation cam is located at the intersectionof the major and minor axes of the ellipse, the first separation cam 402is non-circular symmetric with respect to the center of the first axisof rotation. Similarly, the second separation cam 404 may be ellipticalin cross section with a major axis and a minor axis. The separationradius r_(s) of the second separation cam 404 generally corresponds tothe major axis of the ellipse while the non-separation radius r_(ns) ofthe second separation cam generally corresponds to the minor axis of theellipse. While the second axis of rotation 420 of the second separationcam is located at the intersection of the major and minor axes of theellipse, the second separation cam 404 is non-circular symmetric withrespect to the center of the second axis of rotation 420. Theconfiguration of these separation cams enables the separation cams to bepositioned such that the separation radius r_(s) of the separation camsis greater than or equal to the distance d_(CL) between the center ofthe axis of rotation of the separation cam and the center line C_(L) ofthe conveyance pathway 122, as described above, and that the distanced_(CL) between the center of the axis of rotation of the separation camand the center line C_(L) of the conveyance pathway 122 is greater thanthe non-separation radius r_(ns) of the separation cam, also asdescribed above.

Based on the foregoing, it should be understood that separation camswith various cross-sectional shapes may be used in the separationapparatuses described herein. In general, the separation cams of theseparation apparatuses described herein are constructed with aseparation radius r_(s) and a non-separation radius r_(ns) such that, aseach cam is rotated about its respective axis of rotation, the camdefines a separation sweep area and a non-separation sweep area, both ofwhich are centered on the axis of rotation. The separation sweep area isgreater than the non-separation sweep area. For example, FIG. 7schematically depicts a first separation sweep area 506 and a firstnon-separation sweep area 508 of a first separation cam 502. FIG. 7 alsoschematically depicts a second separation sweep area 510 and a secondnon-separation sweep area 512 of a second separation cam 504.

Moreover, in some embodiments described herein, the sum of thenon-separation radius r_(ns) of the first separation cam (i.e., r_(ns1))and the non-separation radius r_(ns) (i.e., r_(ns2)) of the secondseparation cam is less than or equal to the sum of the distance betweenthe center point of the axis of rotation of the first separation cam(i.e., r_(ns1)) and the center line C_(L) of the conveyance pathway andthe distance d_(CL) between the center point of the axis of rotation ofthe second separation cam and the centerline C_(L) of the conveyancepathway (i.e., r_(ns2)) minus the thickness of the thickness Ts of thecontinuous ribbon of brittle material 900 drawn on the conveyancepathway 122 (i.e., r_(ns1)+r_(ns2)≦(d_(CL1)+d_(CL2)−T_(s)). Configuringthe separation cams such that this relationship is satisfied results inthe separation cams being periodically completely disengaged from thecontinuous ribbon of brittle material as the cams are rotated.

Referring again to FIGS. 1-3, the separation apparatuses describedherein may be used to separate discrete sheets of brittle material fromcontinuous ribbons of brittle material such as glass, ceramic, orglass-ceramic materials. The surfaces of these materials may besusceptible to damage, such as nicks, scratches, cracks or the like.Accordingly, in order to prevent the contact faces 114, 116 of theseparation cams 102, 104 from damaging the continuous ribbons of brittlematerial, the contact faces 114, 116 of the separation cams 102, 104 mayinclude a nosing material 112 which mitigates damage to the surfaces ofthe continuous ribbons of brittle material. In the embodiments describedherein, the nosing material may be formed from a variety of materialsincluding, without limitation, silicone, aluminum, Torlon®, PEAK, andUHMW. The nosing is not limited to any particular cross-sectionalgeometry, but may be square, rounded or a point contact.

In some embodiments, the nosing material 112 may extend across theentire width of the separation cam. Alternatively, the nosing material112 may extend across less than the entire width of the separation cam.For example, in FIGS. 1 and 2 the nosing material 112 of the firstseparation cam 102 extends across the entire width of the firstseparation cam 102. However, the nosing material 112 of the secondseparation cam 104 is only positioned proximate the ends of the secondseparation cam 104 and not in the middle of the second separation cam104. A separation apparatus 100 with separation cams having nosingmaterial configured as depicted in FIGS. 1 and 2 is particularly usefulfor preventing contact with quality areas of the continuous ribbon ofbrittle material on at least one side of the continuous ribbon. Thephrase “quality areas” as used herein, refers to a central region of thecontinuous ribbon of brittle material which is spaced apart from thelateral edges of the continuous ribbon of brittle material.

While FIGS. 1 and 2 depict a separation apparatus in which the nosingmaterial extends across the entire width of the first separation cam andthe nosing material of the second separation cam extends across lessthan the entire width of the separation cam, it should be understoodthat the separation apparatus may be constructed such that the nosingmaterial extends across the entire width of both the first and secondseparation cams or, alternatively, such that the nosing material extendsacross less than the entire width of both the first and secondseparation cams.

Referring now to FIG. 8, an alternative embodiment of a separation cam602 is schematically depicted. In this embodiment, the contact face 614of the separation cam 602 is formed from a roller element 620 which isrotatably attached to the separation cam 602. The roller element 620 maybe formed from the same material and/or have the same Shore A hardnessas the nosing material described above. In this embodiment, the axis ofrotation 613 of the roller element 620 is parallel with and offset fromthe axis of rotation 618 of the separation cam 602. Utilizing aseparation cam 602 in which the contact face 614 comprises a rollerelement 620 further reduces the friction between the separation cam 602and a surface of the continuous ribbon of brittle material which theseparation cam 602 periodically contacts, thereby mitigating thepotential for damage to the continuous ribbon of brittle material.

Referring now to FIG. 9, an alternative embodiment of a separationapparatus 150 is schematically depicted. In this embodiment, theseparation apparatus 150 further comprises a third separation cam 126positioned on the same side of the conveyance pathway as the firstseparation cam 102. The third separation cam 126 has an axis of rotationwhich is coaxial with the first separation cam 102. The separationapparatus 150 may also comprise a fourth separation cam 128 positionedon a same side of the conveyance pathway as the second separation cam104. The fourth separation cam 128 may have an axis of rotation which iscoaxial with the second separation cam 104. In this embodiment, thethird separation cam 126 may be directly coupled to the first separationcam 102 and the first drive mechanism 106, such as when the thirdseparation cam 126 and the first separation cam 102 are coupled with acommon axle. Similarly, the fourth separation cam 128 may be directlycoupled to the second separation cam 104 and the second drive mechanism108, such as when the fourth separation cam 128 and the secondseparation cam 104 are coupled with a common axle. However, in anotherembodiment (not shown), each of the third separation cam 126 and thefourth separation cam 128 are independently rotated by separate drivemechanisms and decoupled from both the first separation cam 102 and thesecond separation cam 104. Separation apparatuses which include a thirdseparation cam 126 and a fourth separation cam 128 may be used toprevent contact with the quality areas of a continuous ribbon of brittlematerial separated with the separation apparatus 150. In the embodimentof the separation apparatus 150 depicted in FIG. 9 the separationapparatus is depicted with substantial spacing between opposingseparation cams for purposes of illustration and clarity. In practice,the spacing between opposing separation cams is much less to facilitatecontacting and displacing a continuous ribbon of brittle material drawnon the conveyance pathway 122 between the separation cams, as depictedin FIG. 11. For example, the spacing between separation cams can beequal to or less than 1 mm, depending on the thickness of the continuousribbon of brittle material.

While the separation apparatuses disclosed herein have been describedand illustrated as including first and second separation cams, it shouldbe understood that, in some embodiments, the separation apparatuses mayinclude a single separation cam, such as when the separation apparatusincludes only the first separation cam instead of first and secondseparation cams. In these embodiments, the first separation cam may haveany of the geometrical configurations as described above with respect toseparation apparatuses which include first and second separation cams.

Methods of using the separation apparatuses described herein will now bedescribed in more detail with specific reference to FIGS. 1-2 and 10-11.

Referring now to FIGS. 1-2 and 10-11, a continuous ribbon of brittlematerial, such as a continuous glass ribbon, is drawn on the conveyancepathway 122 in a draw direction 140 which, in this embodiment, is asubstantially vertical direction. The center through the thickness Ts ofthe continuous glass ribbon is at least initially aligned with thecenterline C_(L) of the conveyance pathway 122. As the continuous glassribbon is drawn, the ribbon may be scored across the width of the ribbonthereby creating a vent 920 in at least one surface of the ribbon. Theterm “vent,” as used herein, refers to a defect, such as a nick, scratchor the like, introduced into the surface of the substrate which servesas an initiation site and guide for controlled crack propagation duringsubsequent separation. The vent generally does not extend through thethickness of the substrate. The scoring operation for forming the ventmay be performed using conventional scoring techniques including,without limitation, mechanical scoring and/or laser scoring. As thecontinuous scored glass ribbon 900 is conveyed along the conveyancepathway 122, the first separation cam 102 of the separation apparatus100 is rotated such that at least a portion of a contact face 114 of thefirst separation cam 102 is periodically positioned across thecenterline C_(L) of the conveyance pathway 122 such that the contactface 114 of the first separation cam 102 can contact a first surface 902of the continuous scored glass ribbon 900 and displace a portion of thecontinuous scored glass ribbon 900 in a first displacement direction 142(FIG. 11). Simultaneously, the second separation cam 104 of theseparation apparatus 100 is rotated such that at least a portion of acontact face 116 of the second separation cam 104 is periodicallypositioned across the centerline C_(L) of the conveyance pathway 122such that the contact face 116 of the second separation cam 104 cancontact a second surface 904 of the continuous scored glass ribbon 900and displace a portion of the continuous scored glass ribbon 900 in asecond displacement direction 144 which is opposite the firstdisplacement direction 142 (FIG. 11). In the embodiment shown in FIG.10, the first separation cam 102 and the second separation cam 104 arerotated in opposite directions as indicated by arrows 146, 148. However,it should be understood that the first separation cam 102 and the secondseparation cam 104 may be rotated in the same direction, such as whenthe first separation cam and the second separation cam comprises rollerelements, as described above.

The continuous scored glass ribbon 900 is directed into the separationapparatus on the conveyance pathway 122 which is disposed between thefirst separation cam 102 and the second separation cam 104. The firstdrive mechanism 106 and the second drive mechanism 108 are synchronizedsuch that at least a portion of the contact face 114 of the firstseparation cam 102 and at least the portion of the contact face 116 ofthe second separation cam 104 periodically extend across the centerlineof the conveyance pathway 122 and contact opposing surfaces of thecontinuous scored glass ribbon 900 at a separation time and periodicallydo not extend across the centerline and do not simultaneously contactopposing surfaces of the continuous scored glass ribbon 900 at anon-separation time.

For example, in some embodiments, the rotation of the first separationcam 102 and the second separation cam 104 may be synchronized with oneanother and the draw speed of the glass sheet such that a vent 920formed in the glass is located between the first separation cam 102 andthe second separation cam 104 (i.e., the vent 920 is located downstreamof the first separation cam 102 and upstream of the second separationcam 104) as the contact face 114 of the first separation cam 102contacts a first surface 902 of the continuous scored glass ribbon 900and the contact face 116 of the second separation cam 104 contacts asecond surface 904 of the continuous scored glass ribbon 900. As shownin FIG. 11, the first separation cam 102 displaces a portion of thecontinuous scored glass ribbon 900 from the centerline C_(L) of theconveyance pathway 122 in a first displacement direction 142 and thesecond separation cam 104 simultaneously displaces a portion of thecontinuous scored glass ribbon 900 from the centerline C_(L) of theconveyance pathway 122 in a second displacement direction 144 oppositethe first displacement direction. The simultaneous displacement of thescored glass ribbon in the first displacement direction 142 and thesecond displacement direction 144 propagates the vent 920 through thethickness of the glass ribbon thereby separating a discrete glasssubstrate 950 from the continuous scored glass ribbon 900 along a scoreline of the continuous scored glass ribbon.

In another embodiment (not shown), simultaneous displacement of thecontinuous scored glass ribbon 900 in the first displacement direction142 and the second displacement direction 144 may occur when the vent920 is positioned on the contact face 114 of the first separation cam102, on the contact face 116 of the second separation cam 104, slightlyupstream of the first separation cam 102, or slightly downstream of thesecond separation cam 104.

Referring now to FIG. 12, Referring now to FIG. 12, a separationapparatus 101 which includes a single separation cam (i.e., the firstseparation cam 102) is schematically depicted separating a glass sheetfrom a continuous ribbon of brittle material. The continuous ribbon ofbrittle material, such as a continuous glass ribbon, is drawn on theconveyance pathway 122 in a draw direction 140 which, in thisembodiment, is a substantially vertical direction. The center throughthe thickness Ts of the continuous glass ribbon is at least initiallyaligned with the centerline C_(L) of the conveyance pathway 122. As thecontinuous glass ribbon is drawn, the ribbon may be scored across thewidth of the ribbon thereby creating a vent 920 in at least one surfaceof the ribbon. As the continuous scored glass ribbon 900 is conveyedalong the conveyance pathway 122, the first separation cam 102 of theseparation apparatus 100 is rotated such that at least a portion of acontact face 114 of the first separation cam 102 is periodicallypositioned across the centerline C_(L) of the conveyance pathway 122such that the contact face 114 of the first separation cam 102 cancontact a first surface 902 of the continuous scored glass ribbon 900and displace a portion of the continuous scored glass ribbon 900 in afirst displacement direction 142.

The continuous scored glass ribbon 900 is directed into the separationapparatus on the conveyance pathway 122. The first drive mechanism 106is synchronized with the drawing rate of the glass ribbon such that atleast a portion of the contact face 114 of the first separation cam 102periodically extends across the centerline of the conveyance pathway 122and contacts the surface of the continuous scored glass ribbon 900 at aseparation time and periodically does not extend across the centerlineat a non-separation time. For example, in some embodiments, the rotationof the first separation cam 102 may be synchronized with the draw speedof the glass sheet such that a vent 920 formed in the glass is locateddownstream of the first separation cam 102 as the contact face 114 ofthe first separation cam 102 contacts a first surface 902 of thecontinuous scored glass ribbon 900. As shown in FIG. 12, the firstseparation cam 102 displaces a portion of the continuous scored glassribbon 900 from the centerline C_(L) of the conveyance pathway 122 in afirst displacement direction 142. The displacement of the scored glassribbon in the first displacement direction 142, in conjunction with theweight of the glass ribbon downstream of the first separation cam 102and/or a circular idler roll 390 positioned downstream of the firstseparation cam 102, propagate the vent 920 through the thickness of theglass ribbon thereby separating a discrete glass substrate 950 from thecontinuous scored glass ribbon 900 along a score line of the continuousscored glass ribbon.

In another embodiment (not shown), displacement of the continuous scoredglass ribbon 900 in the first displacement direction 142 may occur whenthe vent 920 is positioned on the contact face 114 of the firstseparation cam 102 or slightly upstream of the first separation cam 102.

Referring now to FIG. 13, the separation apparatuses described hereinmay be used in conjunction with a glass manufacturing system in order toproduce discrete glass substrates from continuous ribbons of glass. Forexample, one embodiment of an exemplary glass manufacturing system 200is schematically depicted in FIG. 13. The glass manufacturing systemutilizes a separation apparatus 100 as depicted in FIG. 1. The glassmanufacturing system 200 includes a melting vessel 210, a fining vessel215, a mixing vessel 220, a delivery vessel 225, a fusion draw machine(FDM) 241, a scoring apparatus 160 and a separation apparatus 100. Glassbatch materials are introduced into the melting vessel 210 as indicatedby arrow 212. The batch materials are melted to form molten glass 226.The fining vessel 215 has a high temperature processing area thatreceives the molten glass 226 from the melting vessel 210 and in whichbubbles are removed from the molten glass 226. The fining vessel 215 isfluidly coupled to the mixing vessel 220 by a connecting tube 222. Themixing vessel 220 is, in turn, fluidly coupled to the delivery vessel225 by a connecting tube 227.

The delivery vessel 225 supplies the molten glass 226 through adowncomer 230 into the FDM 241. The FDM 241 comprises an inlet 232, aforming vessel 235, and a pull roll assembly 240. As shown in FIG. 2,the molten glass 226 from the downcomer 230 flows into an inlet 232which leads to the forming vessel 235. The forming vessel 235 includesan opening 236 that receives the molten glass 226 which flows into atrough 237 and then overflows and runs down two sides 238 a and 238 bbefore fusing together at a root 239. The root 239 is where the twosides 238 a and 238 b come together and where the two overflow walls ofmolten glass 226 rejoin (e.g., refuse) before being drawn downward bythe pull roll assembly 240 to form the continuous glass ribbon. Thecontinuous glass ribbon is initially passed through a scoring apparatus160 where a partial vent is formed in at least one surface of thecontinuous glass ribbon, thereby forming a continuous scored glassribbon 900. The scoring apparatus 160 is synchronized with the drawspeed of the glass ribbon such that the continuous glass ribbon isscored at regular intervals. Thereafter, the continuous scored glassribbon 900 is directed through the separation apparatus 100 where thecontinuous scored glass ribbon 900 is separated in to a discrete glasssubstrates 950, as described above.

It should now be understood that the apparatuses and methods describedherein may be used for separating continuous glass ribbons into discreteglass substrates. The apparatuses described herein may be utilized toincrease the draw speed of glass manufacturing systems and therebyimprove manufacturing throughput. Specifically, the use of rotating camsin a fixed frame or enclosure enables a continuous glass ribbon to beseparated with a fixed or stationary device rather than a device whichtravels with the glass ribbon as the ribbon is conveyed. This eliminatesthe necessity of cycling the separation device upstream followingseparation of a glass substrate from the glass ribbon and alsoeliminates the step of matching the speed of the separation apparatuswith the conveyance speed of the glass ribbon. Elimination of both ofthese steps allows the draw speed of the glass manufacturing apparatusto be increased as the glass separation device is no longer a ratelimiting step.

Based on the foregoing, it should be understood that a plurality ofaspects of the methods and apparatuses described herein are discloses.In a first aspect, a separation apparatus for separating a sheet ofbrittle material along a scoring line includes a first separation campositioned adjacent to a conveyance pathway, wherein the firstseparation cam is rotatably coupled to a first drive mechanism rotatingthe first separation cam about a first axis of rotation. The first drivemechanism rotates the first separation cam such that at least a portionof a contact face of the first separation cam periodically extendsacross a centerline of the conveyance pathway. The first drive mechanismis synchronized with a draw rate of the sheet of brittle material suchthat at least the portion of the contact face of the first separationcam extends across the centerline of the conveyance pathway at aseparation time and periodically does not extend across the centerlineof the conveyance pathway at a non-separation time.

In a second aspect, a separation apparatus for separating a sheet ofbrittle material along a scoring line includes a first separation campositioned adjacent to a sheet conveyance pathway. The first separationcam is rotatably coupled to a first drive mechanism rotating the firstseparation cam about a first axis of rotation such that rotation of thefirst separation cam defines a first separation sweep area and a firstnon-separation sweep area centered on the first axis of rotation. Thefirst separation sweep area is greater than the first non-separationsweep area. A second separation cam positioned opposite and downstreamof the first separation cam on the sheet conveyance pathway. The secondseparation cam is rotatably coupled to a second drive mechanism rotatingthe second separation cam about a second axis of rotation. Rotation ofthe second separation cam defines a second separation sweep area and asecond non-separation sweep area centered on the second axis ofrotation. The second separation sweep area is greater than the secondnon-separation sweep area. A first separation sweep radius r_(s1) of thefirst separation sweep area is greater than a first distance d₁ betweenthe first axis of rotation and a centerline of the conveyance pathway.The second separation sweep radius r_(s2) of the second separation sweeparea is greater than a second distance d₂ between a center point of thesecond axis of rotation and a centerline of the conveyance pathway. Thefirst rotational drive mechanism and the second rotational drivemechanism synchronously rotate the first separation cam and the secondseparation cam such that at least a portion of a contact face of thefirst separation cam and at least a portion of the contact face of thesecond separation cam periodically extend across the centerline of theconveyance pathway at the same time.

A third aspect includes the separation apparatus of the first aspect,wherein a second separation cam positioned opposite from and downstreamof the second separation cam on the conveyance pathway. The secondseparation cam is rotatably coupled to a second drive mechanism rotatingthe second separation cam about a second axis of rotation. The seconddrive mechanism rotates the second separation cam such that at least aportion of a contact face of the second separation cam periodicallyextends across the centerline of the conveyance pathway. The first drivemechanism and the second drive mechanism are synchronized such that atleast the portion of the contact face of the first separation cam and atleast the portion of the contact face of the second separation camperiodically extend across the centerline of the conveyance pathway at aseparation time and periodically do not extend across the centerline ofthe conveyance pathway at a non-separation time.

A fourth aspect includes the separation apparatus of the third aspect,wherein the first drive mechanism and the second drive mechanism arecoupled to a common drive source.

A fifth aspect includes the separation apparatus of any of the firstthrough fourth aspects, wherein the contact face of the first separationcam comprises a nosing material.

A sixth aspect includes the separation apparatus of the fifth aspect,wherein the nosing material of at least one of the first separation camand the second separation cam extends across an entire width of thecontact face.

A seventh aspect includes the separation apparatus of the fifth aspect,wherein the nosing material of at least one of the first separation camand the second separation cam extends across less than an entire widthof the contact face.

An eighth aspect includes the separation apparatus of any of the secondthrough seventh aspects wherein the first separation cam and the secondseparation cam are rotated in opposite directions.

A ninth aspect includes the separation apparatus of any of the firstthrough eighth aspects wherein the contact face of the first separationcam comprises a roller element.

A tenth aspect includes the separation apparatus of any of the firstthrough ninth aspects wherein the first separation cam is elliptical incross section.

An eleventh aspect includes the separation apparatus of any of the firstthrough ninth aspects wherein the first separation cam is circular incross section and the first axis of rotation is non-concentric with acenter of the first separation cam.

A twelfth aspect includes the separation apparatus of any of the secondthrough eleventh aspects wherein the conveyance pathway is verticallyoriented and the first separation cam and the second separation cam arespaced apart in a horizontal direction and offset from one another in avertical direction.

A thirteenth aspect includes the separation apparatus of any of thesecond through twelfth aspects wherein rotation of the first separationcam defines a first separation sweep area and a first non-separationsweep area centered on the first axis of rotation, wherein the firstseparation sweep area is greater than the first non-separation sweeparea and rotation of the second separation cam defines a secondseparation sweep area and a second non-separation sweep area centered onthe second axis of rotation, wherein the first separation sweep area isgreater than the first non-separation sweep area.

A fourteenth aspect includes the separation apparatus of any of thethird through thirteenth aspects wherein a first separation sweep radiusr_(s1) of the first separation sweep area is greater than a firstdistance d₁ between the first axis of rotation and a centerline of theconveyance pathway and a second separation sweep radius r_(s2) of thesecond separation sweep area is greater than a second distance d₂between a center point of the second axis of rotation and a centerlineof the conveyance pathway.

A fifteenth aspect includes the separation apparatus of the fourteenthaspect wherein the first non-separation sweep area has a firstnon-separation sweep radius r_(n1), the first non-separation sweep areahas a second non-separation sweep radius r_(n2), andr_(n1)+r_(n2)≦(d₁+d₂−T_(s)), wherein Ts is a thickness of a sheet ofbrittle material drawn between the first separation cam and the secondseparation cam.

In a sixteenth aspect, the separation apparatus of any of the secondthrough fifteenth aspects further includes a third separation campositioned on a same side of the conveyance pathway as the firstseparation cam and having an axis of rotation which is coaxial with thefirst separation cam and a fourth separation cam positioned on a sameside of the conveyance pathway as the second separation cam and havingan axis of rotation which is coaxial with the second separation cam.

A seventeenth aspect, includes the separation apparatus of the sixteenthaspect wherein the third separation cam is rotatably coupled to thefirst drive mechanism; the fourth separation cam is rotatably coupled tothe second drive mechanism; and the first drive mechanism and the seconddrive mechanism are synchronized such that at least the portion of thecontact face of the third separation cam and at least the portion of thecontact face of the fourth separation cam periodically extend across thecenterline of the conveyance pathway at a separation time andperiodically do not extend across the centerline of the conveyancepathway at a non-separation time.

An eighteenth aspect includes a method of separation a glass substrateutilizing a separation apparatus of any of the first through seventeenthaspects.

In a nineteenth aspect, a method for separating a glass substrate mayinclude conveying a scored glass ribbon on a conveyance pathway in aconveyance direction. The scored glass ribbon may be directed between afirst separation cam and a second separation cam. The second separationcam may be positioned downstream of the first separation cam in theconveyance direction. The first separation cam and the second separationcam may be positioned on opposite sides of a centerline of theconveyance pathway. The first separation cam may be rotated such that atleast a portion of a contact face of the first separation cam isperiodically positioned across the centerline of the conveyance pathwayand the contact face of the first separation cam periodically contacts afirst surface of the scored glass ribbon and displaces at least aportion of the scored glass ribbon from the centerline of the conveyancepathway in a first displacement direction. The second separation cam maybe rotated simultaneously with the first separation cam such that atleast a portion of a contact face of the second separation cam isperiodically positioned across a centerline of the conveyance pathwayand the contact face of the second separation cam periodically contactsa second surface of the scored glass ribbon and displaces at least aportion of the scored glass ribbon from the centerline of the conveyancepathway in a second displacement direction opposite the firstdisplacement direction. The simultaneous displacement of the scoredglass ribbon in the first displacement direction and the seconddisplacement direction separates the scored glass ribbon along a vent inthe scored glass ribbon.

In a twentieth aspect, a method for forming a glass substrate includesdrawing a continuous glass ribbon in a substantially vertical directionfrom a forming apparatus. The continuous glass ribbon may be scored toform a vent as the continuous glass ribbon is drawn in the substantiallyvertical direction. Thereafter, a first portion of the continuous scoredglass ribbon may be periodically displaced in a first direction which isnon-parallel with the substantially vertical direction as the continuousscored glass ribbon is drawn in the substantially vertical direction.Additionally, a second portion of the continuous scored glass ribbon maybe periodically displaced in a second direction opposite the firstdirection as the continuous glass ribbon is drawn in the substantiallyvertical direction. The second portion of the continuous scored glassribbon may be downstream of the first portion of the continuous scoredglass ribbon. The second portion of the continuous scored glass ribbonis displaced simultaneously with the first portion of the continuousscored glass ribbon such that a glass substrate is separated from thecontinuous glass ribbon along the vent.

A twenty-first aspect includes the method of the nineteenth aspect,wherein the conveyance direction is a substantially vertical direction.

A twenty-second aspect includes the method of the twentieth aspect,wherein the first portion of the continuous scored glass ribbon isperiodically displaced by a first separation cam and the second portionof the continuous scored glass ribbon is periodically displaced by asecond separation cam positioned downstream of the first separation cam.

A twenty-third aspect includes the method of any of the nineteenth ortwenty-second aspects, wherein the scored glass ribbon is displaced inthe first displacement direction and the second displacement directionwhen the vent of the scored glass ribbon is downstream of the firstseparation cam and upstream of the second separation cam.

A twenty-fourth aspect includes the method of any of the nineteenth andtwenty-second through twenty-third aspects, wherein the first separationcam is rotated about a first axis of rotation such that the firstseparation cam defines a first separation sweep area and a firstnon-separation sweep area centered on the first axis of rotation,wherein the first separation sweep area is greater than the firstnon-separation sweep area; and the second separation cam is rotatedabout a second axis of rotation such that the second separation camdefines a second separation sweep area and a second non-separation sweeparea centered on the second axis of rotation, wherein the secondseparation sweep area is greater than the second non-separation sweeparea.

A twenty-fifth aspect includes the method of the twenty-fourth aspect,wherein a separation radius r_(s) of the first separation sweep area isgreater than a distance d_(CL) between a center of the first axis ofrotation and a centerline of the conveyance pathway; and a separationradius r_(s) of the second separation sweep area is greater than adistance d_(CL) between a center point of the second axis of rotationand a centerline of the conveyance pathway.

A twenty-sixth aspect includes the method of the twentieth aspect,wherein the vent is positioned between the first portion of thecontinuous scored glass ribbon and the second portion of the continuousscored glass ribbon.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments describedherein without departing from the spirit and scope of the claimedsubject matter. Thus it is intended that the specification cover themodifications and variations of the various embodiments described hereinprovided such modification and variations come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method for separating a glass substrate, themethod comprising: conveying a continuous scored glass ribbon on aconveyance pathway in a conveyance direction; directing the continuousscored glass ribbon between a first separation cam and a secondseparation cam positioned downstream of the first separation cam in theconveyance direction, wherein the first separation cam and the secondseparation cam are on opposite sides of a centerline of the conveyancepathway and the first separation cam and the second separation cam arenon-circular-symmetric about their respective axes of rotation; rotatingthe first separation cam such that at least a portion of a contact faceof the first separation cam is periodically positioned across thecenterline of the conveyance pathway and the contact face of the firstseparation cam periodically contacts a first surface of the continuousscored glass ribbon and displaces at least a portion of the continuousscored glass ribbon from the centerline of the conveyance pathway in afirst displacement direction; rotating the second separation camsimultaneously with the first separation cam such that at least aportion of a contact face of the second separation cam is periodicallypositioned across a centerline of the conveyance pathway and the contactface of the second separation cam periodically contacts a second surfaceof the continuous scored glass ribbon and displaces at least a portionof the continuous scored glass ribbon from the centerline of theconveyance pathway in a second displacement direction opposite the firstdisplacement direction; and wherein a simultaneous displacement of thecontinuous scored glass ribbon in the first displacement direction andthe second displacement direction separates the continuous scored glassribbon along a vent of the continuous scored glass ribbon.
 2. The methodof claim 1, wherein the conveyance direction is a substantially verticaldirection.
 3. The method of claim 1, wherein the continuous scored glassribbon is displaced in the first displacement direction and the seconddisplacement direction when the vent of the continuous scored glassribbon is downstream of the first separation cam and upstream of thesecond separation cam.
 4. The method of claim 1, wherein: the firstseparation cam is rotated about a first axis of rotation such that thefirst separation cam defines a first separation sweep area and a firstnon-separation sweep area centered on the first axis of rotation,wherein the first separation sweep area is greater than the firstnon-separation sweep area; and the second separation cam is rotatedabout a second axis of rotation such that the second separation camdefines a second separation sweep area and a second non-separation sweeparea centered on the second axis of rotation, wherein the secondseparation sweep area is greater than the second non-separation sweeparea.
 5. The method of claim 4, wherein: a separation radius r_(s) ofthe first separation sweep area is greater than a distance d_(CL)between a center of the first axis of rotation and a centerline of theconveyance pathway; and a separation radius r_(s) of the secondseparation sweep area is greater than a distance d_(CL) between a centerpoint of the second axis of rotation and a centerline of the conveyancepathway.
 6. A method for forming a glass substrate comprising: drawing acontinuous glass ribbon in a substantially vertical direction from aforming apparatus; scoring the continuous glass ribbon to form a vent asthe continuous glass ribbon is drawn in the substantially verticaldirection to form a continuous scored glass ribbon; displacing,periodically, a first portion of the continuous scored glass ribbon in afirst direction which is non-parallel with the substantially verticaldirection with a first rotating separation cam as the continuous scoredglass ribbon is drawn in the substantially vertical direction;displacing, periodically, a second portion of the continuous scoredglass ribbon in a second direction opposite the first direction with asecond rotating separation cam as the continuous scored glass ribbon isdrawn in the substantially vertical direction, wherein: the firstrotating separation cam and the second rotating separation cam arenon-circular-symmetric about their respective axes of rotation; thesecond portion of the continuous scored glass ribbon is downstream ofthe first portion of the continuous scored glass ribbon; and the secondportion of the continuous scored glass ribbon is displacedsimultaneously with the first portion of the continuous scored glassribbon such that a glass substrate is separated from the continuousscored glass ribbon along the vent.
 7. The method of claim 6, whereinthe vent is positioned between the first portion of the continuousscored glass ribbon and the second portion of the continuous scoredglass ribbon.
 8. The method of claim 6, wherein the first portion of thecontinuous scored glass ribbon is periodically displaced by a firstseparation cam and the second portion of the continuous scored glassribbon is periodically displaced by a second separation cam positioneddownstream of the first separation cam.